3D printed gears and spring toggle a switch made of conductive plastic, which changes the state of a 3D printed antenna to convey data to a Wi-Fi receiver. (Image credit: University of Washington)

Researchers from the University of Washington have advanced civilization a few more years into the future by developing the first 3D printed plastic objects that are capable of collecting useful data and communicate that data to connected devices wirelessly without any electronics or batteries. What’s more, the researchers are making their CAD models available to the public, providing 3D printing enthusiasts the ability to create their own.

According to UW electrical engineering doctorate student Vikram Lyer, “Our goal was to create something that just comes out of your 3-D printer at home and can send useful information to other devices,but the big challenge is how do you communicate wirelessly with Wi-Fi using only plastic? That’s something that no one has been able to do before.”

To get the objects to communicate with each other, the researchers used 3D printed gears, springs and switches to translate motion into information that is transmitted over a 3D printed antenna and received by a wireless receiver. The key to getting these objects to communicate relies on backscatter techniques, more specifically ‘interscatter communication’, which allow electronic devices the ability to communicate by converting Bluetooth signals into Wi-Fi transmissions. Backscatter communications rely on electronics for wireless data transmissions, but in this case, the researchers replaced the electrical components with mechanical motion to perform the same function, similar to how battery-free watches keep time.

A Backscattering technique allows for communication between 3D printed objects and Wi-Fi transmitters and receivers. (Image credit: University of Washington)

Employing a backscatter system allowed the researchers to make use of an antenna (in this case, a strip of 3D printed material made of plastic and copper) to transmit data by reflecting signals emitted by a Wi-Fi router. Data can then be embedded into those reflected signals and decoded by a Wi-Fi receiver. The physical motion then causes springs and gears to engage a conductive switch to intermittently connect or disconnect with the embedded antenna, changing its reflective state into 1’s and 0’s, thereby encoding data into that signal.

This 3D printed flow meter can tell you how much laundry detergent you have left. (Image credit: University of Washington)

The team demonstrated their new system using several different 3D printed tools, including one that acts as a flow meter to keep tabs on liquid laundry soap, an anemometer that measures wind speed and several widgets (a button, knob and slider) that can interact with other smart devices to manipulate things like music volume, lighting and object weight. The team also found that by changing the 3D printed filament to one with iron, they could use magnetic properties to encode information on static objects such as barcodes and inventory tabs and could even be adapted for use for robot/object interaction, making it easier for robots to identify specific objects.